From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0214617727; Mon, 27 May 2024 19:30:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716838248; cv=none; b=Q6+1+Exz5IasjSEIPn6ELOY2ynK0xl0TzipLuJ5wep3O8Mznj8btUY1vFZ2SBG2g2hzrn0sng2DVxL1CFLdlZBTeO1iFG2JuiAdJu5k7IgaOHNOjOSWNamUhRwFusaFV9j5gfdAXfn6GeSBRcLAAHyuSoKkx0X04SSo+yD9bbls= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716838248; c=relaxed/simple; bh=aaKtoPfXSxfMzLXmqrLygcykBBojEDnFBLL8lGf3Ybk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=W17OJPCjeZgH2KWwNobVMG+tOQoXysn4MddY8sRF/cPoA7k/L2/EpK50rObDmAAR/NFv0z5805ZB2KyxMIlwKkf5Wb9PBPuhvQaH6JIyFVn6cOqjfyvXMyoEUSlpTybGodZPUvIAT1Y3ISZ3eF1PDjzcvfa5G/vtZGLmV4EaO/A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=XM+90COa; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="XM+90COa" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 83E5BC2BBFC; Mon, 27 May 2024 19:30:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1716838247; bh=aaKtoPfXSxfMzLXmqrLygcykBBojEDnFBLL8lGf3Ybk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XM+90COaqk0btmUBMjdC+0e2QDoSSPkOrdrrvY4mLaNJARMvrrj/Wyq9YsiFBCeWY rIr6CbNLO6AuNqiicPpIpBJcyohqjGh7Ksi8oY2frnGfgKCuhfQLkE6pQK8sVOVIdX dMg68ju4yQ8zCA6l4zC3hjO+S8ifdIaUKjoiGJgQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dan Carpenter , Duoming Zhou , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.8 322/493] ax25: Fix reference count leak issues of ax25_dev Date: Mon, 27 May 2024 20:55:24 +0200 Message-ID: <20240527185640.806850712@linuxfoundation.org> X-Mailer: git-send-email 2.45.1 In-Reply-To: <20240527185626.546110716@linuxfoundation.org> References: <20240527185626.546110716@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Duoming Zhou [ Upstream commit b505e0319852b08a3a716b64620168eab21f4ced ] The ax25_addr_ax25dev() and ax25_dev_device_down() exist a reference count leak issue of the object "ax25_dev". Memory leak issue in ax25_addr_ax25dev(): The reference count of the object "ax25_dev" can be increased multiple times in ax25_addr_ax25dev(). This will cause a memory leak. Memory leak issues in ax25_dev_device_down(): The reference count of ax25_dev is set to 1 in ax25_dev_device_up() and then increase the reference count when ax25_dev is added to ax25_dev_list. As a result, the reference count of ax25_dev is 2. But when the device is shutting down. The ax25_dev_device_down() drops the reference count once or twice depending on if we goto unlock_put or not, which will cause memory leak. As for the issue of ax25_addr_ax25dev(), it is impossible for one pointer to be on a list twice. So add a break in ax25_addr_ax25dev(). As for the issue of ax25_dev_device_down(), increase the reference count of ax25_dev once in ax25_dev_device_up() and decrease the reference count of ax25_dev after it is removed from the ax25_dev_list. Fixes: d01ffb9eee4a ("ax25: add refcount in ax25_dev to avoid UAF bugs") Suggested-by: Dan Carpenter Signed-off-by: Duoming Zhou Reviewed-by: Dan Carpenter Link: https://lore.kernel.org/r/361bbf2a4b091e120006279ec3b382d73c4a0c17.1715247018.git.duoming@zju.edu.cn Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ax25/ax25_dev.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/net/ax25/ax25_dev.c b/net/ax25/ax25_dev.c index f16ee5c09d07a..52ccc37d5687a 100644 --- a/net/ax25/ax25_dev.c +++ b/net/ax25/ax25_dev.c @@ -39,6 +39,7 @@ ax25_dev *ax25_addr_ax25dev(ax25_address *addr) if (ax25cmp(addr, (const ax25_address *)ax25_dev->dev->dev_addr) == 0) { res = ax25_dev; ax25_dev_hold(ax25_dev); + break; } spin_unlock_bh(&ax25_dev_lock); @@ -88,7 +89,6 @@ void ax25_dev_device_up(struct net_device *dev) list_add(&ax25_dev->list, &ax25_dev_list); dev->ax25_ptr = ax25_dev; spin_unlock_bh(&ax25_dev_lock); - ax25_dev_hold(ax25_dev); ax25_register_dev_sysctl(ax25_dev); } @@ -129,7 +129,6 @@ void ax25_dev_device_down(struct net_device *dev) unlock_put: dev->ax25_ptr = NULL; spin_unlock_bh(&ax25_dev_lock); - ax25_dev_put(ax25_dev); netdev_put(dev, &ax25_dev->dev_tracker); ax25_dev_put(ax25_dev); } -- 2.43.0